System Recommendations - User Guide - NA-N4-BASE-25 - NA-S-N4-1000 - NA-S-N4-10000 - NA-S-N4-100000 - NA-S-N4-250 - NA-S-N4-2500 - NA-S-N4-50000

System Recommendations - User Guide - NA-N4-BASE-25 - NA-S-N4-1000 - NA-S-N4-10000 - NA-S-N4-100000 - NA-S-N4-250 - NA-S-N4-2500 - NA-S-N4-50000 - NA-S-N4-UNL

Siemens N4 Appliance User Guide

Product Family

Appliances

Content Language

English

Content Type

Technical Documentation > User Guide

Document No

A6V101007427_en_l

Download ID

A6V101007430

Stock No.

P55691-L199

P55691-L200

P55691-L201

P55691-L202

P55691-L203

P55691-L204

P55691-L205

P55691-L210

Product No.

NA-N4-BASE-25

NA-S-N4-1000

NA-S-N4-10000

NA-S-N4-100000

NA-S-N4-250

NA-S-N4-2500

NA-S-N4-50000

NA-S-N4-UNL

Access level

Internet

File Type

html

System Recommendations

For optimized system performance, Siemens recommends the following tuning policies:

Siemens N4 Appliance Tuning Policy Recommendations.
Policy	Value	Notes
Min Write Time	0 minutes (default)	Applies to writable points. Specifies the minimum amount of time allowed between writes. Provides a method to throttle a rapidly-changing value so that only the last value is written. If this property value is 0 (default), this rule is disabled and all value changes attempt to write.
Max Write Time	0 minutes (default)	Applies to writable points. Specifies the maximum “wait time” before rewriting the value, in case nothing else triggers a write. Any write action resets this timer. If this property value is 0 (default), this rule is disabled (no timed rewrites). This is how often you want the station to take control over the BACnet device.
Write on Start	False (default)	Applies to writable points. Determines behavior at station startup. If True, a write occurs when the station first reaches “steady state.” If False (default), a write does not occur when the station reaches “steady state.” This setting allows the station to take control of the BACnet device when it first starts. Doing this can put a load on the station while it is trying to start by adding multiple write commands to the station.
Write on Up	True (default)	Allows the station to take control when the device transitions from Down to Up.
Write on Enable	True (default)	Allows the station to take control when the device transitions from Disabled to Enabled.
Stale Time	10 minutes (varies based on polling policy)	Confirms that the device is working properly, but raises awareness that a point has not been updated in a reasonable amount of time. A longer period of time for slower polling rates and a shorter period of time for faster polling rates.
UseCOV	False (true for the Siemens_COVPpolicy, false for the Siemens polled policies)	If set to True, and assigned points are under a BacnetDevice that supports the Subscribe COV service, any necessary updates (Niagara proxy subscriptions) are attempted using BACnet COV subscriptions to the device. If the subscription attempt succeeds, the Read Status property of the point’s BacnetProxyExt displays `COV`. If the subscription attempt for a proxy point fails, normal polling is used and the Read Status property displays `Polled`.
Use Confirmed COV	True (default)	If UseCOV is enabled (set to True) and assigned points are under a BacnetDevice that supports Confirmed COV notifications, any necessary updates (Niagara proxy subscriptions) are attempted using BACnet Confirmed COV subscriptions to the device. If UseCOV is not enabled (set to False), the value of this property is ignored (true for the Siemens_COVPpolicy, false for the Siemens polled policies).
COV Subscription Lifetime	15 minutes	The lifetime, in minutes, for which Niagara will subscribe for COV notifications, and then, if necessary, periodically re-subscribe. A value of zero means an indefinite lifetime, although this is not guaranteed to persist across resets of the server device. Note: Do not use zero in Siemens installations! If UseCov is set to False, the value of this property is ignored.